A diaphragm valve disclosed in Patent Literature 1 includes a valve body provided with a fluid channel, an annular valve seat provided on the peripheral edge of the fluid channel, a metal diaphragm that has a spherical surface and that is pressed against or separated from the valve seat to close or open the fluid channel, a diaphragm presser that has a lower end having a spherical surface and serving as a pressing surface and that presses the diaphragm, and an actuator that moves the diaphragm vertically.